The present invention pertains generally to heating systems for homes, buildings, etc., utilizing a reverse cycle refrigeration process with earthen material being a heat source.
In the prior art a number of heating systems have been proposed which utilize a buried ground coil through which a medium passes for heating by the earthen material. Such systems utilize, briefly, a reverse refrigeration process wherein a circulated medium is heated by passage through a buried coil and subsequently pressurized prior to flow through a liquid-to-air heat exchanger. The medium, cooled by passage through the heat exchanger, is directed back in an altered state through a buried ground coil. An expansion valve serves to meter a partially vaporized medium flow to the ground coil.
Obvious advantages to such a system if certain drawbacks were overcome include the avoidance of fossil fuel cost and their environmental impact.
While several attempts have been made over several years to embody such heating systems in a practical system for single family or larger dwellings, none of the proposed systems have found wide acceptance. One significant problem encountered by the prior art systems was the freezing of the earthen material by the system ground coil. Such freezing rendered the system inoperable and in some cases imparted stresses to adjacent building foundations damaging same. Heretofore it has been proposed that a coil be buried in serpentine configuration to adequately subject the medium to ground heat. The burial of lenghty conduit runs constituted a problem partuclarly when the ground area within which the conduit was buried was of restricted size resulting from various subterranean obstructions and/or real property size limitations.
The use of heat pumps in home and building heating systems incurs periodic pump servicing or replacement at considerable expense to the user. Heat pumps, as currently known, are subjected to severe pressures and temperatures which adversely affect their life.